<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Document</title>
        <style>
            *{
                margin: 0px;
                padding: 0px;
                list-style: none;
            }
            .a1{height: 497px;
                width: 968px;
                 background: url("imges/背景.jpg") repeat-x;
                 margin: auto;
            }
            .a2{
                height: 378px;
                width: 968px;
                background: red;
                margin: 48px auto;
            }
            .a3{
                height: 50px;
                width: 968px;
                background: lime;
                margin: 27px auto;
            } 
            .a4 {
                    margin-top: 14px;             
                    float: left;}
        </style>
    </head>
    <body>
        <div class="a1"><div class="a4">
            <img src="imges/logo.png" alt=""height=44px>
        </div></div>
        <div class="a2"></div>
        <div class="a3"></div>
    </body>
</html>